Why isnt't this a win?

In the Queen's Gambit stalemate was not mentioned, therefore most new players don't know what that is... even though it is a common word in English (and many other languages I guess)
In the Queen's Gambit stalemate was not mentioned, therefore most new players don't know what that is... even though it is a common word in English (and many other languages I guess)
I just had a great game and when I finally wanted to celebrate my win... It was a draw!


Could someone explain to me why? What is this obscure rule?
Thanks in advance!